Lubricating device



Patented May 26, 1941 2,242,262 LUBRICATING DEVICE Eugene .1. Bar,Beverly, Masa, ass gnmto United :Shoe Corporation, Borough of Fl N. 1.,a corporationo! Newlerlcy Application May 3, 1938, Serial No. 205,750

This invention relates to lubricatin devices and is herein illustratedas embodied in a machine having roller bearings'carrying a highspeedshaft.

The use of bearings having balls, or any other type of rolling elements,in connection with a shaft intended to rotate at a high speed is, ofcourse, desirable, as they reduce bearing friction to a minimum; but thehighest possible speed at which such bearings can be operated withoutexcessive heating depends, to a great extent, upon the effectiveness oftheir lubrication. That is, high speed bearings when lubricated with oilin the ordinary manner are likely to become overheated because of thefact that, when a substantial amount of oil is present in the bearings,considerable work (which is changed into heat) mint be performed on theoil particles in moving them from place to place in the bearings andrelatively to each other.

In view: of the foregoing, one of the principal objects of the presentinvention is to provide a device for supplying lubricant in an adequatebut so minute a quantity to roller bearings that they may be operated ata substantially higher speed -than has been possible heretofore.

To this end the invention provides, as one feature thereof, a housingarranged to support a bearing carrying a high-speed shaft, the housingbeing spaced from the ends of the bearing and means out of contact withan oil supply in the bottom of the housing for directing small particlesof oil into the air in the housing, thereby creating a fog of lubricant,and circulating the fog throughout the housing and through the bearingfrom one end to the other. Thus the bearing will receive an adequate andcontinually replenished deposit of lubricant which is so minutely thinthat no appreciable amount of work will be expended upon the lubricant.Accordinsly, there will be no appreciable heating in the oil or bearingalthough it is operated at very high speed.

In the illustrated construction the above-mentioned means for creatingand circulating the fog of lubricant, in accordance with another featureof the invention is constituted by a turbulator carried by the shaft andadapted to induce an air current adjacent thereto which is faster thanthe rotary motion of the air at any other point lengthwise of the shaft,thereby providing suiiicienit turbulence in the fog of lubricant toinsure its circulation through the bearings as mentioned above.

In order to insure against excessive lubrication of the bearing such aswould result from its being immersed in or sprayed by oil or the like,means, constituting another feature of the invention, is provided in theillustrated machine for maintaining the lubricant or oil in the housingat such a level that even, when its surface is disturbed by theturbulence of the fog in the housing, it always remains below and out ofcontact with any of the moving parts of the hearing and the shaft.Preferably this means is in the form of a barometric feeding device, theposition of which may be adjusted to vary the height of the level of thelubricant in the housing, as required by difierent operating conditions.

In the drawing,

Fig. l is a view, partly in vertical section, of a bearing housingprovidedwith a high speed shaft arranged to run in ball bearings, and anillustrative bearing lubricating device embodying the invention;

Fig. 2 is a transverse sectional view, along the line ll of Fig. 1, asseen in the direction of the arrows, and showing a barometric feeddevice by which the oil is maintained at a constant level in the bearinghousing to suit constant operating conditions; and

Fig. 3 is a similar transverse sectional view of a barometric feeddevice in which the level of the oil may be adjusted to suit difieren-toperating conditions and then be maintained at that level.

The invention is illustrated in the accompany. ing drawing as applied tothe mounting of a cutter shaft of a machine for trimming the outer edgeof a. shoe sole, such a. machine being known to shoe manufacturers as anedge-trimming machine. A portion of the frame of such a machine isillustrated at Ill in Fig. 1. A housing 12 is secured to the frame bymeans of a series of screws ll. At each end of the housing are mountedball-bearings having outer races l6, l8 and inner races 20, 22respectively. The outer races l6, l8 are a sliding fit in bored surfacesin the housing l2 but the inner races 20, 22 fit tightly on a cuttershaft 24 having shoulders against which the races 20, 22 are seated.

The bearing is designed to operate under a spring load, as is the usualpractice, to maintain it in proper adjustment. For this purpose, awasher 26 mounted to bear against the righthand ball race 18 (Fig. 2) ispressed to the left by means of a series of compression springs 28inserted in recesses 30 in an end-bearing cap 34 secured to theend ofthehousing l2 by means of screws 36. The pressure of the springs 28against the washer 26 urges the ball race 18 toward the left, the thrustof which race is transmitted by the adjacent balls, the inner race 22and shaft 24 to the inner race 20, and thence through the balls therein,to the outer race I at the left-hand end of the housing. The outer raceit is held in the housing by an elongated bearing cap 38 secured to theleft-hand end of the housing by screws ll. In this way the shaft runssmoothly with all radial and lengthwise backlash taken up.

The usual edge-trimming cutter (not shown) is mounted on a conical seat42 on the left-hand end of the shaft 24 in the usual manner. n theopposite end of the shaft is mounted a grooved pulley M for driving thesame.

Within the housing I 2 is a chamber 48, the

bottom of which serves as a reservoir for a supply of liquid oil andincludes a sump portion 48. Integral with the shaft 24 and locatedmidway between the ball bearings is a collar 50 which serves to supp y amixture of air and oil in the form of a vapor or "fog" to the bearings,as will be described. Other shapes may be used instead of a collar, andall such devices may be termed turbulators as they create turbulencewithin the housing II. It should be observed that, whether the shaft ismoving or is at rest, the level of the liquid oil is always below thelevel of the rotatable collar 50, or other turbulator and always belowthe balls in the races I6 and II. Thus, the liquid oil is always out ofcontact with moving parts. It is believed that the "fog" is created andcirculated substantially as described below.

When the collar II is rotated at the high speed of the illustratedmachine (which is at approximately 11,000 revolutions per minute), itsperiphery travels at somewhat over a mile per minute. A current of airis dragged around by the friction between the air and the collar 50 andis finally thrown oil tangentially from the collar at theabove-mentioned high speed and blows across the top surface of theliquid oil, causing a groove to be formed in the upper surface of theoil beneath the collar. This groove or depression is indicated at A(Fig. 1) by the line which represents the oil level directly below theaxis of the shaft 24 longitudinally of the chamber ll. As this currentof air sweeps across the surface of the oil, it gathers up minuteparticles of oil to form a Vapor or fog" which fills the chamber 46above the surface of the liquid oil. When this current, which travelsfaster opposite the collar than elsewher strikes the inside wall of thehousing, it divides as indicated by the arrows 3-13 and flows insubstantially equal parts toward the two ball bearings as indicated bythe arrows C-C. Owing to the spaces between the races and around theindividual balls on both sides of the bearings, the oil fog passesfreely across the path of travel of the balls or rollers and over theraceways, leaving a minute film thereon. It then passes through thespaces D and E and eventually unites with the main body of liquid oil inthe chamber for recirculation. The ports F and G provide means forequalizing the level of the liquid oil and for the bearings to preventflooding thereof.

The rotation of the air produced by the rotation of the collar 50 (and,to a less extent, the shaft N), producing the heretofore mentionedgroove indicated at A (Fig. 1), also tends to drag the liquid oil aroundwith it so that the oil is slightly lowered on the side of the chamberwhere this air first strikes it. and is raised slightly on the oppositeside. This effect is indicated by J in Fig. 2 (at the plane indicated by11 in Fig. 1) and by the line K also in Fig. 2, which shows the bottomof the groove in the liquid oil directly beneath the collar II (at A inFig. 1).

It should be noted that the annular space between the housing I! and theshaft 24, with its collar 50, is constricted by the presence of liquidoil in the lower portion thereof. This constriction evidently acts as abailie to increase the pressure of the current of air and oil as itstrikes this baille, so as to assure more complete circulation to allportions of the bearings.

In order to prevent dust and dirt from reaching the bearings and toprevent the egress of oil therefrom, each of the bearing caps 38 and I4is provided with baille grooves 00 tively. Any oil that collects inthese grooves drains back into the lower part of the chamber ll throughducts M and I. Only an extremely small clearance space is providedbetween the caps and the shaft at these points and it has been foundthat these grooves adequately accomplish the purpose for which they areprovided, even after months of use.

As previously stated, a barometric feed device is provided to controlthe level of the liquid oil in the chamber 46. Two form of such a deviceare shown in the drawing. a non-adjustable is to be preferred because,by its use, the most suitable height of the oil at will. However, whenthe operating conditions are substantially constant. as in the operationof the illustrative trimming machine, and the required height of the oillevel has been previously determined, the non-adjustable form is to bepreferred.

Best shown in Fig. 2 is a usual form of a barometric feed device havinga glass container 10 which is secured to the cover 12 of a usual type ofoil cup 14 in the following manner. The cover 12 is threaded at 10 toreceive a split nut ll,

level may be obtained shown in Fig. 2. It may then be locked in positionby means of a bail 90 secured to the cover and a thumb screw 92.

In the adjustable form of barometric feed device, shown in Fig. 3, afitting I communicating with the duct 83, is tapped into the side of thehousing I2 and is adapted to receive an oil tube I02 (similar to 82)With a sliding but oiltight fit. An oil container I04 is mounted on topof a cap I06 to which the tube I02 is fixed (by a split nut and gasketsas in the other construction). One or more washers I08 may be placedbetween the cap I06 and fitting I00 in order to adjust the bottom of thetube to any required height. In order to prevent oil from spilling fromthe container when it is being inserted in or removed from the fittingI00, 2. spring-pressed valve H0 is arranged to close the opening in theupper end of the tube I02 whenever the latter is disengaged from thefitting I00. The valve H0 is held in its open position when the tube I02is assembled in the fitting I00 so as to establish barometric feedconditions, by a valve stem II2 which strikes the fitting shortly beforethe tube I02 is lowered to its operative position.

Summarizing the operation of the illustrated machine, as the peripheryof the collar 50 travels at somewhat over a mile per minute, the airsurrounding it iscarried over the surface of the oil at such a highspeed that minute particles of,oii are taken from the surface of the oiland mixed with the air in the chamber 46 to form the above-describedvapor or fog.

Since the speed of the air traveling across the surface of the oil isgreater beneath the collar than elsewhere along the shaft, the level ofthe oil beneath the collar is lowered in a groove-like formation and acurrent is induced in the air adjacent to the collar which increases theturbulence of the fog and thus insures a vigorous circulation of the fogthrough the casing. Owing to the spaces D and E between the ends of thehousing and the bearings, and also between the rollers themselves in theraceways, the fog passes across the path of the rollers to lubricatethem. It should be noted that, at all times, whether the shaft ismoving, or is at rest, the level of the liquid oil is always below thelevel of the rotatable collar 50 and always below the rollers in theraces of the roller bearings. The liquid oil is thus always maintainedout of contact with moving parts by the barometric feed device referredto above.

The amount of oil gathered by the current of air from the collardecreases with the distance of the oil level beneath the lowest part ofthe collar, and of the diflerent operating conditions, an increasedspeed, a wider collar or a collar of larger diameter, all require alower oil level to reduce the supply of oil to the optimum amount andvice versa. However, there may be considerable deviation from theoptimum level without adversely affecting the operation of the devicesubstantially.

It has been found by test that a machine, in which the present inventionis used, will operate without leakage or overheating for several monthsand without refilling or requiring any other attention to thelubricating system on the part of the operator. Applicant does not wishto be limited to the use of air in his invention, as many other gaseousmaterials, such as those used in refrigeration, will function equally aswell.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

1. A lubricating system for a roller bearing carrying a high speed shafthaving, in combination, a housing for said shaft and bearing, saidhousing being spaced from the ends of said bearing and adapted to holdliquid oil, and a turbulator mounted on the shaft for creating a mixtureof air and oil in the housing and circulating it through the bearingfrom one side thereof to the other, said turbulator having its lowestportion always above the highest level of the oil in the housing.

2. A lubricating system for a roller bearing carrying a high speed shafthaving, in combination, a housing surrounding said bearing and shaft andarranged to contain a supply of liquid lubricant in its lower portion,and a rotary turbulator in the housing and located out of contact withthe liquid lubricant therein, said turbulator causing a rapid passing ofair across the surface of the liquid lubricant whereby minute particlesthereof are picked up, mixed with the air and circulated solely as avapor or "fog in the housing and in the bearing.

3. A lubricating system for spaced roller bearings carrying a high speedshaft having, in combination, a housing for said shaft and bearingsarranged to contain a supply of liquid oil, and a turbulator operated bythe shaft for forcing air across the surface of the liquid oil to createa mixture of air and oil in the housing and to circulate it in saidbearings, said turbulator being located out of contact with the liquidoil at all times.

4. A lubricating system having, in combination, a housing arranged tocontain a. supply of liquid lubricant in its lower portion, a high speedshaft passing through said housing, a roller bearing for the shaft, anda smooth concentric collar on said shaft and rotating therewith, therotating collar creating a turbulence of the air in the housing by whichminute particles of liquid lubricant are picked up from the surface ofthe liquid and are circulated in the housing and in the bearing solelyas a vapor or fog, said shaft,

collar and the moving parts ofv said bearing being located at all timesout of contact with said liquid lubricant in the housing.

5. A lubricating system for relatively moving parts comprising, incombination, a housing surrounding the parts and arranged to contain asupply of liquid lubricant, and a high speed rotary turbulator in thehousing and located out of contact with the liquid lubricant therein,said turbulator causing a rapid passing of air across the surface of theliquid lubricant whereby minute particles thereof are picked up, mixedwith the air. and circulated solely as a vapor or "fog in the housing tolubricate said parts.

EUGENE J. RAY.

